Field of the Disclosure
This disclosure relates generally to monitoring the discharge of a fluid from a relief valve. More particularly, the disclosure relates to an apparatus for indicating the status of a relieve valve, in particular, the degree to which the valve is open.
Background Information
Industrial processes and pipelines for fluids utilize surge relief valves to protect against injury or damage due to unwanted or sudden increases in fluid pressure or flow rate, which will also be referred to as process-upsets. A surge relief valve is coupled to a process vessel or a process line, i.e. piping, for which protection is needed. When the vessel or the flow line experiences a process-upset, the surge relief valve opens to relieve the process pressure. The portion of fluid discharged through the surge relief valve is typically directed to a storage tank, to another pipeline, to another portion of the industrial process, or to the environment. If directed to a storage tank, the discharged fluid may be subsequently measured and pumped back into the process or the pipeline. In comparison, for many types of fluids, environmental discharges from a surge relief valve are more challenging and require submitting a report to one or more government agencies and possibly paying a monetary fine, influenced by the total amount of fluid discharged, which is roughly estimated. For any destination of the discharged process fluid, it would be advantageous to have equipment or a method for performing a higher-quality estimation, or for making a measurement of the amount of process fluid that discharges from a surge relief valve without the addition of a traditional flow meter, which would impose an additional flow restriction and perhaps an undesired level of cost.